There are many types of viewers known in the art. These viewers have been constructed in various shapes and sizes, some of which are relatively inexpensive to manufacture. Examples of variations on viewers can be found in U.S. Pat. No. 3,850,505 which discloses a Viewmaster.TM. type of device.
In designing and producing viewers, one universally recognized principle is that a clear and distinct image requires proper alignment of the optical components of the viewer with the image(s). Another recognized principle is that a viewer must compensate for differences in eyesight among users, i.e. being near sighted or farsighted, to ensure that a broad range of users can use the viewer and still see a clear image. To that end, viewers must employ some form of focusing means. Additionally, principles of optics teach that extraneous light entering a viewer decreases the clarity of the image. For example, in three-dimensional stereoscopic viewers, a viewer that excludes extraneous light enhances the three-dimensional effect and increases the clarity and illusion of reality of the image.
The demands of the market have imposed additional requirements on viewers. Specifically, for mass market purposes, there is a need for inexpensive viewers that are foldable or collapsible into compact and easy to handle configurations. For example, collapsible stereoscopic viewers have been used in promotional mailers. To meet this objective, collapsible viewers have been devised such that they collapse into mailable configurations U.S. Pat. No. 5,136,423 issued to Curtin on Aug. 4, 1992 discloses a stereoscopic viewer that collapses into mailable form. The collapsible viewers of the prior art, however, have sacrificed some of the principles discussed above to create viewers that are more marketable in the promotional products industry.
One example of a collapsible stereoscopic viewer is disclosed in U.S. Pat. No. 5,309,281 ('281) issued to Rover on May 3, 1994. Rover teaches a stereoscopic viewer incorporating a foldable hexagonal frame. The hexagonal frame supports a lens bearing wall that is opposite to an image-bearing wall. To collapse the device of this invention, the user simply pushes two opposite walls of the frame together. To focus the viewer disclosed in the '281 patent, the user squeezes the hexagonal frame to adjust the distance between the lens-bearing wall and the image-bearing wall. The device of the '281 patent, however, makes no provision to keep out extraneous light. Additionally, the assembly does not result into a rigid structure. Therefore, the alignment between the lenses and the images is often imprecise.
U.S. Pat. No. 5,136,423 ('423) issued to Curtin discloses a collapsible stereoscopic viewer with a folding septum wall that locks the foldable assembly into a box configuration. Although the viewer disclosed in the '423 patent ensures alignment of the lens with the image, this device makes no provision for the user to focus the viewer to accommodate for differences in eyesight. Additionally, this structure has no components to shut out extraneous light.
U.S. Pat. No. 4,846,553 ('553) issued to Rice discloses yet another collapsible viewer that folds into mailable form. Rice describes his foldable viewer as a bellows-like fold construction, wherein the top, bottom and side walls have transverse fold lines that allow the viewer to be collapsed. The '553 patent teaches that these transverse fold lines also allow the user to focus the viewer by squeezing the top and bottom walls together. However, according to the '533 patent, the viewer does not lock into a rigid structure to ensure optical alignment of the stereoscopic components. Additionally, the configuration of the viewer allows extraneous light to enter the viewer through gaps between the various walls of the viewer.
U.S. Pat. Nos. 4,175,828 ('828), 4,253,732 ('732), and 4,357,073 ('073) issued to Carver all disclose different versions of a collapsible stereoscopic viewer. These references disclose a viewer where two opposing lateral walls have extensions that bend around the rear wall and attach to form a channel for the receipt of a film strip having pairs of stereoscopic images. These references also disclose a focus feature created by transverse fold lines in the lateral walls much like the Rice '533 patent. These references do not disclose a viewer that locks into a rigid assembly. Accordingly, misalignment of the images and the optical means may result from this viewer's inability to "lock" into a rigid structure.
While the viewers of the prior art fulfill their respective objectives and requirements, they do not include or suggest a viewer that provides an enhanced and immersive image by the configuration of large images positioned in close proximity to large magnification lens. Further, the collapsible viewers of the prior art do not describe or suggest a box-like collapsible viewer having a side wall lock and tensioning mechanism that tenses the box-like viewer assembly into a rigid structure. The prior art viewers also do not describe or suggest a collapsible viewer wherein the side walls further predispose a lensbearing wall to create a means to focus the viewer. Furthermore, the prior art viewers do not describe or suggest a collapsible stereoscopic viewer wherein the lens bearing wall flexes inwardly to slightly diverge the focal axes of the lenses in the horizontal direction to allow the user to view a wider field.
A significant aspect of the viewer is that it achieves the described high image magnification and wide field of view while folding to a size no larger in its dimensions than a standard cd-jewel case, in large part due to the arcuate fold in the viewers side flaps. This allows the viewer a unique marketing advantage in packaging with other products such as cd-rom software and music CD's.